Vapor-from-liquid separator apparatus



Aug. 11, 1953 T. RAVESE ET AL 2,648,397

VAPOR-FROM-LIQUID SEPARATOR APPARATUS Filed March 9, 1948 2 Sheets-Sheetl Water Level 74 INVENTORS Thomas Ruvese 8 Earl V. Bentley Aug. 11, 1953T RAVESE ETAL VAPOR-FROM-LIQUID SEPARATOR APPARATUS 2 Sheets-Sheet 2Filed March 9, l348 Patented Aug. 11, 1953 VAPOR-,FBDM-LIQUID SEPARATDRAPPARATIJS Thomas Ravese, Port-Chester,'N. y andiEarl'v.

Bentley, Philadelphia, Pa, assignors to .Combustion Engineering, Inc,, avcorpor:;1 .ti o1 1 of Delaware Application March 9, 1948,'Serial No.13,804

(Cl. t81;)

3 Claims.

1 Our invention relates to equipment for securing dry steam frommixtures of steam and .water as taken from the vaporizing tubes (orother surfaces) of steam generating boilers, and it has specialreference to vapor-from-liquid separator devices that are installable inthe steam and water drums of such boilers to accomplish the purposenamed and that also are useful in other applications.

In modern boilers for both marine and stationary application thesteamand water. drum usual- 1y contains equipment for: (1) distributingincoming feed water; (2) separating steam from water; and (3) deliveringsteam with a minimum of entrainment of Water or solids. The general termdrum internals covers this class of equipment, which has assumed greatimportance as the rates of steam liberation have increased.

Broadly stated, the object of our invention is to improve the design,extend the usefulness and better the performance of the steam separatorportions of such drum internal apparatus.

A more specific object is to increase theiquantity of steamofqacceptable drynessand purity which maybe taken from a steamand waterdrum of'given diameter. and length, therebypermitting the size, cost andweight requirements of the drum tobe reducedin a givensteam-generatinginstallation.

Another object is to enable the drumecontained steam separator units todeliver steam of acceptable dryness and purity even though the waterlevel in the drum may rise substantially above the designed level (suchas the drum s center line) Aiurther object is toovercome-difiicultiesdue to foaming which heretoforehave reducedtheattainable separator capacity when dissolved, and suspended solids andother unavoidable impurities are present in the boiler water.

A still vfurther object is to enable the drumcontained steam separatorunits to deliver steam of acceptable dryness and purity even though thesolids content of theboiler water maybesubstantially greater thannormally prevalent values and even though exceedingly sharp increases insuch solids content (as due to large chemiqal dosage of the boiler waterorto leakysurfacecondensers which contaminate the feed water) may occur.

An additional object istol assure eifectivesteam separation in the drumandjdischargeqof.acceptably dry steam therefrom when the steam "andwater mixture ;from the generating tubes comes into thedrum atvelocities ashigh as 50 to '75 feet per second (as compared with theconventional 15 to 25 foot per second rates customary in the past).

Other objects and advantages Will become apparent fromthe followingdescription of an illustrative embodiment of the invention when read inconjunction with the accompanying drawings wherein:

Figure 1 is a simplified-schematic representation (in the nature of-avertical section) of a steamgenerating installation that has a steam andwater drum equipped with the improved separator apparatus hereindisclosed;

Figure 2 is a transverse section of the steam andiwateri drum of Figure1 enlarged to show how steam separator devices constructed in accordancewith one embodiment of the invention may satisfactorily beinstalledtherein;

":Figure 3 is-an enlarged-top-plan-like representation of one of thenewsepa-rator units as viewed from line 3-3 of each of Figures 2 and 4;

.Figure lis a vertical section through the same separator unit as viewedfrom line 4-4 of Figure 3; .and

Figure 5 is a simplified section (to reduced scale) on line -5'5 ofFigure 2 showing thirteen of'the separator units positioned in two rowswithin the drumalong-thelength thereof.

The vapor-from-liquidseparator devices of our invention are especiallywell adapted for use on forced circulation steam boilers and on naturalcirculation steam boilers with liberal circulating head; they may, moreover, advantageously be employed to obtain a high degree of steam andwater separation in steamvgenerators of a wide variety of types andcapacities. Illustrative of these isthe steam generator shown in Figure1.

The steam generator of Fz'gure 1 the tubes in rows a b are fed fromasecondary vaporizing circuit l6 positioned at a somewhat higherelevation in the boiler furnace; and the tubes in row [-22 are fed froma third circuit 18 which lines the combustion chamber wall (not shown)opposite the'burners I5.

The illustrative boiler furnace of Figure 1 is further provided with aforced circulation pump 20 (two such pumps may be used in parallel) forpassing the water from drum is bottom discharge outlet 2| into a maindistributing header 22 and thence through the three vaporizing circuitsl4, l6 and I8 earlier named; with a superheater 24 in the heatingchamber through which saturated steam leaves drum ID by way of topoutlet 25 to have its temperature further raised before enteringsuperheated steam header 26; and with an inlet water connection 28through which boiler feed water is admitted into the drum in a mannerlater to be described. To lay the basis for subsequent description itwill be assumed that this steam generator of Figure 1 is designed tooperate at pressures of 1200 pounds per square inch and higher; alsothat its three vaporizing circuits I4, l6 and I8 are jointly capable ofgenerating steam and passing same through tubes l2 into steam and waterdrum H) at rates up to 240,000 pounds per hour.

The steam and water drum 10 In the illustrative steam generator ofFigure l the steam and water drum H) has an internal diameter of 42inches and a length (see Figure of feet between drum ends; the steamoutlet therefrom takes the form of a single pipe 25 leading out of thedrum top midway of the drum length; the water outlet 2| from the drumbottom takes the form of two downcomer pipes (see Figures 1 and 5)respectively leading out of the two drum ends and acting in parallel tocarry the drum leaving water into pumps 20 for circulation throughheader 22 and boiler vaporizing circuits l4, l6 and IS; the vaporizingcircuit tubes |2 of drum entering rows abc-d e have the customary smallinside diameter (such as one inch); the end man hole opening 30 into thedrum has a horizontal dimension of 16' inches and a vertical dimensionof 12 inches; and feed water under suitable pressure is admitted by wayof connection 28 (see Figure 1) through an inlet pipe that enters thedrum by way of a suitable opening (as in the drum rear but not shown).

As the description hereof proceeds it will become apparent that steamand water drums of dimensions, proportions and organizations differingfrom those just described may also be benefltted by the steam separatorimprovements of our invention.

The drum internals of Figure 2 As illustratively represented in Figure 2drum ID has installed therewithin: (1) feed water distributor meanswhich include Submerged pipe 32 perforated as at 33 and supplemented bywater baffle 34; (2) steam-from-water separator means which take theform of centrifugal units 38 projecting upwardly out of the water in twolengthwise rows along drum interior (see Figure 5) and organized to acton all steam and Water mixture that enters the drum by way of generatortubes l2; and (3) dry pipe means 40 for distributin and further dryingthe steam on its way from separator units 38 to outlet pipe 25 in thedrum top.

The feed water admission means here shown utilize connection 28 (seeFigure 1) from which the incoming feed water is conveyed by pipe 28a(see Figure 2) into the midpoint (not shown) of the distributor pipe 32which extends lengthwise through the drums lower portion as indicated.This distributor pipe 32 is closed at both ends and provided along itstop with the spaced openings 33 through which all the incoming feedwater must pass in a way assuring diffusion (aided by baffle plate 34positioned above admission openings 33 along the pipe length) into themain body of drum water submerging the pipe.

For screening any large particles of solid matter out of the water whichleaves the drum by way of the two downcomer outlets 2|, each of thoseoutlets haspositioned around its open top a cylindrical screen 35organized as shown in Figure 2 to require all outlet-entering water(feed from pipe 33 plus discharge from separators 38) first to passthrough the screen. Other equivalent means for diffusing the incomingfeed water through the lower body of drum-contained water and for takingthe feed and discharge water out of the drum are of course useable withour improved separator units 38.

The dry pipe means 40 here shown are the same as those disclosed andclaimed in U. S. Patent No. 2,594,490, issued April 29, 1952, to W. S.Patterson. They comprise a V-shaped plate 4| positioned beneath offtake25 and extending in either direction therefrom for substantially theentire length of the drum but With the two plate edges spaced from thedrum top as indicated at 42; a pair of baffle strips 43 welded along thedrum top interior as shown and further functioning as supports forV-plate 4|; plate holding spacers 44 provided at intervals along thedrum length to secure (as through cap screw connections) V-plate 4| (andtaper strips 46) to support strips 43; a horizontal screen 45 spanning aportion of the V-plate bottom; and taper strips 46 adjustably fixed tothe sides of V-plate 4| and shaped to give each side steam-admissionspace 42 a minimum dimension at the location of steam outlet 25 and aprogressively widening dimension as the outlet location is departed fromlengthwise of the drum.

The V-plate portion beneath screen 45 preferably has one or more drainholes (not here shown) passed downwardly therefrom through the platematerial so that such water as may accumulate in the V-plate 4| may bedrained to a point of lower pressure. Other forms and arrangements ofdry pipe apparatus are of course usable with the improved separatorunits 38 now to be disclosed.

The new separator units 38 Single drum boilers (as typified by Figure 1)require very efficient and compact means to meet current demands forhigh capacity and steam purity. In such boilers steam and water mixtureentering the drum l0 from tubes I2 may consist of two to fifteen or moreparts of water for each part of steam by Weight, but the steam deliveredfrom the drum through outlet 25 preferably should contain less than onequarter of one percent moisture. Moreover, this low moisture content inthe delivered steam must be maintained notwithstanding that the boilerwater from which steam is generated (and which enters drum IO throughtubes l2 along with the steam) contains substantial quantities ofdissolved and suspended solids and other impurities which cannot beavoided.

To provide steam of such dryness the units 38 of Figures 2 through 5have upwardly passed therethrough from a compartment 48 all of the steamand water mixture that is delivered into the drum II] by tubes l2; thatcompartment 48 is enclosed by partition walls 49 which are or- *egeaaeoraganized as fShOWI]. .around the :ends T01 tubes 1'2 and which extendalong the gentiretubeeentering length of the drum to divide the enclosedcompartment space from the remainder of the drum interior; and sevenseparatorunits 38 constituting a right row are mounted along horizontalcompartment wall 49a. while six other similar units 38 constituting .aleft row are supported in similar upright position throughsupplypipesfill which connect into vertical compartment wall 4%.

It will beevident that either a lesser or'greater number of units 38 areuseable dependingupon drum size and quantity of steam to be separatedand that arrangement in less or more than'two rowsis possible; in fact,only a single unitimay be found adequate in certain situations. 'Alsothe arrangement of the compartment 48 may differ from that hererepresented.

As here illustratively shown by Figures2-3-4 each of the units 38comprises an inner upright primary tube 52 connected at its'bottom withcompartment 48 and having substantially straight side walls whichterminate in an open top; spinner blades 54 mounted in the lower portionof I the tube 52 intermediate it and a-central core piece 55; an outerupright skirt tube 56 of larger diameter than the first surroundingprimary tube 52 in-the spaced concentric relation shown and derivingmechanical support therefrom as through studs 5! spaced around-the tubecircumference; a disc-like baffle 58 secured to the top of outer tube 56as by the aid of clamp studs 59 and spannin the annular spacebetween'inner and outer tubes 52 and 55; a steam-collector nozzle orsleeve 6!) supported (as by integral attachment) from bafile 58 abovethe top of inner upright tube 52 in concentric relation thereto and withthe sleeve bottom spacedly projected into the tube top as shown; anupper compartment communicating with the top of nozzle 60 and defined bylower plate 62, upper plates 63 centrally joined with a straighteningvane 54 (see Figure 4), and side plates 65 and 66 (see Figure 3) whichclose the compartment except for the left and right outlet openingsindicated by the Figure 4 arrows; and a stack of corrugated scrubberplates 58 positioned in each of these two outlet openings and theresupported in any suitable manner as by the aid of through bolts 69 and.plate-from-plate spacers E0.

The illustrative unit shown-employs four spinner blades 54 each inclinedfrom the horizontal at an angle of the general order shown with weldconnections to the inner Wall of primary tube a 52 and interfittingsinto the represented slots in central core piece 55. Obviously either agreater or lesser number of these blades may be used and each may betilted either more or less than indicated. The named core piece 55 maysatisfactorily be provided with drain and vent openings H and 72 in thebottom and top thereof. In the represented design the steam collectorsleeve or nozzle 50 has a cross sectional area related to that ofprimary tube 52 in a manner later to be made evident.

Each of this units two scrubberplate. assemblages 68 (left and right)includes a comparatively large number of corrugated plates 68; eachplate is rectangular as shown and is spaced a short distance fromadjacent plates in the scrubber stack; all of these-plates ineachstackare mounted with their corrugation ridges running substantiallyvertically (as indicated) so that water collecting onandbetweenridgescan freely rundown to the :bottomplate edge for discharge cut of the.separator over the downturned lip of lower compartment plate 62; .andthe ridge-toridge spacing along the horizonta1on each-plate '68 side maybe .of the general order represented.

As the description proceeds it will become apparent that otherequivalent mechanical constructions for unit 38 are possible and thatthe unit'itself '(or individual parts thereof) may be made :eitherlargeror smaller (or otherwise altered) dependin upon available drumspace and steam separating requirements.

Operation of new separator um't During normal operation of the steamgenerator ofFigure'l'the water'level in drum In stays close to the drumscenter line as indicated at M inFigure 2; and under such conditionsthe'top edges of'uprighttubes'iz'and 5B in each separator unit 38 .areseveral inches above the drum water 'line'while the scrubber plates 68are even further above'the water level. Thesteam and water mixtureentering the separator units 38 from compartment i8'is preferably passedthrough a perforated plate '15 suitably positioned in that compartment(see Figure 2) to prevent impact of steam-water mixture from evaporatortubes l2a-b-c on the inlet'connections to the separator units 38.

Steam and watermixture passing from compartment d8 upwardly'through theinner'primary tube 52 of each unit 38 is whirled by spinner blades 5 l(either clockwise orcounterclockwise) so that upon reaching the tube topthe mixture rapidly swirls around the tube interior. The heavier (water)portions of the mixture thus follow helical pathsin advancing upwardlyalong the wall of the 'tube 52. In certain special installations .it maybe desirable to set spinner blades 5 to swirl the mixture clockwise insome oflthe units 38 and to produce a counterclockwise swirl in other ofthe separator units Within the same drum.

The Water content of the mixture has a density from as'low as four to ashigh as one hundred times as great as the steam content, depending uponthe mixture pressure; hence the heavier water thus acted upon bycentrifugal force due to the whirling .is concentrated near the Wall ofupright tube 52 while the lighter steam is concentrated toward the tubecenter. Reduced diameter sleeve {it (projecting down into the top ofprimary tube 52) conducts this central concentration of steam directlyupthrough the sleeve and at the same time allows the outer concentrationof whirling water to pass outside of the sleeve as indicated'by'thearrows. Bafile 58 thereupon deflects this discharge water downwardlyinto the space between inner-and outer tubes 52 and 55, through whichspace the water falls (and is forced by pressure from above) downwardlyas indicated aroun'dthe exterior of primary tube 52 and thence intothebo'dy of drum water (see level 14 of Figure 2) inside of outerskirttube 56.

The separator discharge water from tube :55 'is in 1 this wayeffectively prevented from intermingling with the steam in the drumspace above water level 14, thebottom of confined tube-55 beingconsiderably below the drum water level as Figure 2 indicates. Thisconfinement isparticularly beneficialwhen the boiler Water from whichthe steam is generated contains dissolved and suspended solids and otherunavoidable .impurities, the presence of which tends to produce foamingas laterdiscussed.

Upon proper proportionment of the annular water discharge space (seeFigure 4) around the lower edge of steam collector nozzle 60 relative tothe total area for whirling steam and water mixture inside the uprightprimary tube 52, a. considerable portion of the total water will in thisfirst stage of separation be skimmed off from the steam and dischargedfrom the unit 38 downwardly through the space between inner and outertubes 52 and 56; the central stream of thus partially dried steam (whichstill contains a certain quantity of entrained moisture) will thereuponcontinue upwardly through nozzle 50 for subjection to the second stageof separating action.

In the illustrative unit 38 of Figures 2-3-4 said second stage ofseparation occurs in the uppermost secondary drier compartmentcontaining the left and right stacks of scrubber plates '68. In passingupwardly out of nozzle 50 into that compartment, as indicated by thearrows of Figure 4, the total flow of mixture divides at centralstraightening vane 64 into left and right outlet paths whichrespectively include the represented left and right stacks of corrugatedplates 68. As here used, vane 64 translates the initial rotary flow ofthe steam into linear flow for entry into the scrubbers 68. Figure 3shows that to pass between those narrowly separated plates 58 in eachstack the mixture must successively change its direction in zig-zagfashion; and in consequence of this particles of entrained moistureencounter the vertically extending plate ridges and impinge thereon fordownward drainage therefrom under the action of gravity.

By the time the steam has reached the outer edge of each scrubber platestack substantially all of the entrained moisture is in this way removed therefrom. Gravity now carries said removed moisture downwardlythrough the plate valleys between ridges to the lower support member 62at the base of each stack. From that point collected water is urged bythe outflowing steam stream thereabove to the outer edge of member 62(see Figure 4) from which downturned edge the water drips (again seearrows of Figure 4) downwardly into the main body of drum watertherebeneath.

The steam finally emerging from the separator unit by way of secondarydrier plates 68 thus has been successively subjected to a first stage ofwater separation at the top of upright tube 52, and thereafter to asecond stage of moisture separation in the scrubber-plate assemblage 68of the left and right separator outlets. Steam thus passed through andacted upon by each unit is found to have been relieved of moisture to aremarkably high degree.

Separator units 38 show superior efiectiveness The new separator unitsherein disclosed perform outstandingly well under conditions ofpractical steam generator operation. One test set up for verifying thisperformance made use of the earlier described steam generator of Figure1 equipped with the 42 inch by foot drum of Figures 2 and 5 havingpositioned therein, according to the plan of Figure 5, thirteen of theseparator units 38 of Figures 2-3-4 and being further provided with thedry-pipe apparatus 40 of Figure 2 plus the feed water and other partsshown.

The tests were mad under a boiler pressure of 1250 P. S. I. The thirteenseparator units 38 functioned so effectively that steam containing lessthan one quarter of one percent moisture could be taken from the singledrum outlet 25 at the high rate of 240,000 pounds per hour with waterlevel 14 substantially at the drum center line and with approximatelyfour grains per gallon of dissolved solids in the boiler water. Thiscalled for delivery of over 18,400 pounds of dry steam per hour by eachof the thirteen separator units 38. The limit of the stated steam flowrate was imposed not by the separator units 38 under test but instead byportions of the Figure l steam generating unit external to the steam andwater drum l0.

Nor did the reported tests with the Figure 1 steam generator establishan upper limit when th boiler water was totally free of contaminatingsolids. It can, however, be expected (for reasons later to be madeevident) that under such pure boiler water conditions the capacity ofeach separator unit 38 to deliver acceptably dry steam will be evenhigher than the above-stated value attainable with boiler watercontaining dissolved solids in small quantity (four grains per gallon).

The reported tests verified prior data showing that as the solidscontent in the boiler water is increased, the output of acceptably drysteam which can be taken from a steam and water drum (such as l0)becomes progressively less. But notwithstanding this tendency the steamdelivery rates attainable with our new separator units continued far tosurpass the best performance of all comparable steam separator devicesknown to the prior art.

Thus, with boiler water containing 88 grains per gallon dissolved solids(water alkalinity then over 0.38%) it was at the earlier stated pressureof 1250 P. S. I. possible to withdraw from drum 10 of the steamgenerator 198,000 pounds per hour of steam containing twenty-threehundredths of one percent moisture. Total circulation by pumps 20 thenwas 840,000 pounds of steam-water mixture per hour, and the water level'54 in drum I!) then was three inches above the drum center line. Suchelevated level decreased the total steam space below top outlet 25 andthus imposed on the separator units 38 a more severe duty than had thelevel been at or below the drum center line. Even so, each of the units38 delivered over 15,000 pounds of acceptable dry steam per hour; withlower drum levels (and hence more steam space above the water surface14) still higher delivery rates could have been attained.

The concentration of dissolved solids in the boiler water was thereuponraised to 103 grains per gallon. At the earlier-stated pressure of 1250P. S. I. and again with a total pump circulation of 840,000 pounds perhour there were then withdrawn from the drum 190,000 pounds per hour ofsteam containing thirteen hundredths of one percent moisture. Waterlevel was onequarter inch below the drum center line; however, the fullseparator unit capacity was not reached during this test so that an evenhigher delivery rate could (without carryover of steam into the drumstop outlet 25) undoubtedly have been attained.

Steam of the foregoing dryness as released into the drum ID by our newseparator units 38 contains such an exceedingly small quantity ofentrained moisture that the dry-pipe apparatus 40 seldom'is called uponto impart any further drying during passage of the steam out of thedrum. In the described situation the dry pipe apparatus thereforefunctions principally as an aid to '9 proper distribution of the steamflowing into the single outlet pipe 25 (see'Figure 2) from the severalseparator unit 38 positioned lengthwise of the drum (see Figure Thereported tests stillfurther .confirmed that the pressure head requiredto operate ourtnew separator units ts is well withinthemixturecirculating capacity of all forced-circulation boilers andalso of natural-circulation boilers "with liberal circulating head.Measurements duringthe above 1 50 P. S. I. boiler operation with steamseparation rate (by thirteen units) of 185,000 pounds per'hour andmixture circulation of 820,000 pounds per hour showed a-pressure'dropof'fifty inches of 70 F. water (approximately 1.8 P. S. I.:27.76'in'ches equalling one P..S. I.)

between the interior-of"compartment 48 (which feeds the separator units)and the steam space within drum lfi surrounding the separator unitdischarge outlets.

The performance-test program which provided the foregoing dataadditionally established that the efficiency of our new separator units38 is not adversely affected by operation: (a) at drum pressures below1250 P. S. I. (runs were made at 930 P. S. I. and at 650 P. S. 1.); or(b) in which the rate of steam-watermixture circulation (by thesteam-water mixture fromgenerating tubes I2 may satisfactorily bebrought into the drum at greatly increased velocities typified by flowspeeds of from fifty to'seventy-five feet per second. In the-representedtestboiler of Figure 1 such higher mixture-entry velocities accompaniedtotal pump circulation rates having values as stated by the precedingparagraphs.

Salient features of new separator design "The boiler-water solids namedin presenting the foregoing test data were typical of those customarilyencountered in the practical operation of steam generating boilers. Inthe tests stated, such solids were predominantly soda ash and sodium choride accompanied by lesser amounts'of disodium phosphate and starch andsuspended impurities such as calcium salts and iron oxide (the suspendedand undissolved constituents adding about to'the dissolved contentsearlier given). Their presence greatly increased the tendency forfoaming to occur in the steam and water drum 0 with accompanyingtendency for entrained moisture and associated solids to pass ascarry-over from the drum steam'space into outlet 25.

Foaming, like the suds on a glass of good beer,

'isthe building up of bubbles on the drum water surface l4 (see Figure2) until they reach the steam outlet 25. film around thesteam bubble, asit is generated at the heating surface, becomes stabilized by dissolvedandsuspended solids in the water. -In

.other words, the bubble skinbecomes tough and .does-not break readilywhenthe bubble emerges.

Foarndevelops when the water .If .the rate .at-which foam isdelivered-to the drum exceeds. that at which it is destroyed, frotheventually fills the drum. Main causes are quite generally recognized tobe (a) .high dissolved and suspended-solids content; (b) highalkalinitypand (0) presence of oil-that saponifie with the alkalinitytofor-m soap. Moreover, higher than normal.waterlevelin-the drumEllaccentuates dilficulties due to. foaming becauseof the resultantreduction in steamspace between the water surface and the-steam oiftake.

The new separator design herein :disclosed functions with remarkableeffectiveness in minimizing foaming and bubb-le formation at the surfaceof drum water I i. .The water separated out of vthe whirlingmixtureatthe top of inner primary tube 52 is by.the-.surroundedeouter skirt tube56 .closely confinedaround the-primary tube exterior. That confine1nent..compels thenamed tube'discharge water to enter .the main .body

of dru-m'water 14 within anarrowly confined areav substantially-insideofland above the lower endof outerskirttube. 56 (seeFigure'Z)Accordingly, .the bubbles "which may be .present in the downflowingstream .of discharge water tend to'be crushed upon contact with the bodyof ,drum water, notwithstanding that the bubble skin may be toughbecause of a high solids content in the boiler water. Moreover,the'tendency for new bubbles to form upon impingement of thedischargewater stream with the drum waterbo'dyfis minimized by thepressure underwhichsuch impingement occurs and by the narrow confines of the annularspace between inner and outer tubes52 and 56.

Our investigations '(including intensive study and experiment conductedover a period of several years) have further shown that "the completeseparator unit "38 performs best when the steam collector sleeve .Sirhasa cross sectional area withinthe range of'from approximately to about:the cross sectional area of primary tube 52. During development of ournew unit it wasnoted'that the separator efficiency progressivelyimproved as the collector .sleeve size was increased fr.om52% to 582% ofthe primary tube area; that the separator efficiency remainedpractically unchanged as the sleeve size was further increased from 82to 90% of the tube area; and that sleeve size increases above 90% of thetubearea caused the separator eificiency progressively to decrease, .asharp falling offbeing noted 'when the sleeve area was of thetubearea.These observations .thns

indicate the optimum areafor collector sleeve =sleeve"B0)ismarkedly'improved .due to themeliminary treatment received bythe'steamwithin primary tube 52 containing spinner blades 56. In addition toseparating water from the incoming mixture the last named parts arefound also to break up foam bubbles by physically scrubbing themagainstthe primary tube 'wall (during the :earlier 'nentioned lhelical'a'd- 'vanc'em'ent therealong) and the core piece "55 as and after the:mixture passes upwardly through the w'hirleimparting "blades '56. Suchpreliminary break 11p reduces the .foam content of the steam prior 'toentry into scrubber .splates 68 and thereby enables those plates toaccomplish final moisture removal far more effectively than otherwisewould be the case. Still other factors not yet fully understood seemalso to contribute to the named effect.

There accordingly exists between the primary separator parts and thesecondary drier parts of the complete unit 38 a unique and whollyunexpected coaction which substantially adds to the separator unitsoverall performance, as earliergiven test results so strikingly show. Inconsequence the efiectiveness of our complete separator unit greatlyexceeds the direct summation of the results attainable from the primaryseparator parts and from the secondary drier parts when same functionindividually and without the unique coaction just explained.

It will thus be seen that our new separator design has gone a long waytoward overcoming the "foaming difficulties which in the operation ofprior art separators have so seriously limited the effective outputcapacity of the separator when the steam and water mixture passingtherethrough has come from boiler water containing solids of theconcentrations typically encountered in practice.

It would of course be possible to arrange all of the secondary drierplates 68 in a single stack and pass therethrough all of the steam fromcollector sleeve 60. Our experiments, however, have shown balanceddesign gives more uniform distribu- :1

tion of discharge steam into the upper space of drum as well as helpingto reduce the total pressure drop through the complete unit andcontributing to the primary-part coaction earlier named. In eachinstallation all of these secondary driers 68 may be aligned todischarge crosswise of the drum as Figure indicates; they may be reset(upon loosening clamp screws 59) to discharge lengthwise of the drum orin any other angular direction desired; or some may be set for onedischarge direction and some for another.

Other advantages of the new steam separator design herein disclosedinclude simplicity, low cost, ease of assemblage and ready installation.All separator parts lend themselves to easy manufacture and theircombined cost is comparatively small. The lower or "primary assemblageincluding upright tubes 52 and 56 plus spinner blades 54 and core 55 canbe completely put together outside of the drum ID; as can also the upperor secondary assemblage including scrubber plate stacks 68, horizontalbaffle 58 nd nozzle 60.

The lower tube assemblage 52-56, when detached from the upper assemblage6068 (through a loosening of clamp studs 59) can then be brought throughthe standard 12 x 16 inch man hole opening 30 and connected withcompartment 48 (see Figure 2) through the medium of screw threads 18(see Figure 4) on the lower end of upright tube 52s reduced diameterportion 52a. Thereafter, the upper assemblage 6068 may be brought intothe drum through man hole 38, placed on the top of upright tube 56 (seeFigure 4), and there secured through a tightening of clamp studs 59.Such installation requires comparatively little time; all thirteen ofthe units 38 having been installed in drum in (see Figure 5) by one manin only three hours.

Summary From the foregoing it will be seen that we have improved thedesign, extended the usefulness and bettered the performance ofvapor-from-liquid separator apparatus for steam generator and othercomparable use; that we have increased the quantity of steam ofacceptable dryness and purity which may be taken from a steam and waterdrum of given diameter and length (thereby enabling the size, cost andweight requirements of the drum to be reduced in a given steamgeneratinginstallation); that we have enabled the drum-contained steam separatorunits to deliver steam of acceptable dryness and purity even though thewater level in the drum may rise substantially above the designed level(such as the drums center line) that we have overcome difiiculties dueto foaming which heretofore have reduced the attainable separatorcapacity when dissolved and suspended solids and other unavoidableimpurities are present in the boiler Water; that we have enabled thedrum-contained steam separator units to deliver steam of acceptabledryness and purity even though the solids content of the boiler watermay be substantially greater than normally prevalent values and eventhough exceedingly sharp increases in such solids content (as due tolarge chemical dosage of the boiler water or to leaky surface condenserswhich contaminate the feed water) may occur; and that we have assuredeffective steam separation in the drum and discharge of acceptably drysteam therefrom when the steam and water mixture from the generatingtubes comes into the drum at velocities as high as 50 to '75 feet persecond (as compared with the conventional to foot per second ratescustomary in the past).

The here disclosed employment of our new vapor-from-liquid separatorapparatus to accomplish separation of steam from water obviously isillustrative rather than restrictive since devices constructed inaccordance with our invention may with comparable advantage also beemployed to separate some other vapor from some other liquid.

Hence, even though an illustrative embodiment of the invention has beendisclosed and described, it is to be understood that the invention isnot to be limited to practices, form or arrangement shown butcontemplates other alternatives and mechanical equivalents of theapparatus herein illustrated and falling Within the scope of theappended claims.

What we claim is:

1. In a steam separator, an upright primary tube through which steam andwater mixture is upwardly passed, means in said primary tube forimparting to said upflowing mixture a whirling motion which throws watertherefrom outwardly against the tube Wall for discharge over the tubestop edge and which allows moist steam separated from the water tocontinue upwardly out of the tubes central portion, an upright steamcollector sleeve of smaller diameter than said primary tube positionedthereabove to carry said moist steam upwardly from the tubes centralportion, an enclosure in communication with the top of said collectorsleeve for receiving the steam mixture issuing therefrom and fordirecting same out of the separator in two opposed paths ofsubstantially horizontal flow, a steam-flow straightening vane extendingdownwardly from the enclosure top intermediate said opposed paths andacross the collector sleeve at its approximate center, a stack of spacedcorrugated plates disposed in each of said two opposed flow paths withthe plate ridges substantially vertical whereby collector sleevedischarge steam in passing from said enclosure through each stack is bythe plates therein subjected to a scrubbing action which transfers fromthe steam to the vertical plate ridges still further moisture that formsinto water drops which run down the ridges, and baffle means extendingoutwardly from said sleeve beneath the lower edges of the corrugatedplates in each of said two stacks to receive said downrunning water andcause same to be carried out of each plate stack at the steam-exit sidethereof by the separator discharge steam flowing away from the sleeveabove the water between the plates.

2. In a vapor-frorn-liquid separator, an upright primary tube throughwhich vapor and liquid mixture is upwardly passed, means in said primarytube for imparting to said upflowing mixture a whirling motion whichthrows liquid therefrom outwardly against the tube Wall for dischargeover the tubes top edge and which allows vapor from the mixture tocontinue upwardly out of the tubes central portion, an upright vaporcollector sleeve of smaller diameter than said primary tube positionedthereabove to carry said vapor upwardly from the tubes central portion,an enclosure in communication with the top of said collector sleeve forreceiving the vapor mixture issuing therefrom and for directing same outof the separator in two opposed paths of substantially horizontal flow,a vapor-flow straightening vane extending downwardly from the enclosuretop intermediate said opposed paths and across the collector sleeve atits approximate center, a stack of spaced corrugated plates disposed ineach of said two opposed flow paths with the plate ridges substantiallyvertical whereby collector sleeve discharge vapor in passing from saidenclosure through each stack is by the plates therein subjetced to ascrubbing action which transfers from the vapor to the vertical plateridges still further liquid that forms into drops which run down theridges, and baliie means extending outwardly from said sleeve beneaththe lower edges of the corrugated plates in each of said two stacks toreceive said down-running liquid and cause same to be carried out ofeach plate stack at the vapor-exit side thereof by the separatordischarge vapor flowing away from the sleeve above the liquid betweenthe plates.

3. In a steam separator, an upright primary tube through which steam andwater mixture is upwardly passed, means in said primary tube forimparting to said upflowing mixture a whirling motion which throws watertherefrom outwardly against the tube wall for discharge over the tubestop edge and which allows moist steam separated from the water tocontinue upwardly out of the tubes central portion, an upright steamcollector sleeve of smaller diameter than said primary tube positionedthereabove to carry said moist steam upwardly from the tubes centralportion, an outlet passage in communication with the top of saidcollector sleeve for receiving the steam mixture issuing therefrom andfor directing same out of the separator in a flow path which extendsradially with respect to said collector sleeves vertical axis and whichis substantially horizontal, a steam-flow straightening vane extendingdown- \vardly from the top of the outlet passage and in the vicinity ofthe collector sleeves approximate center, spaced corrugated platesdisposed in said radially directed flow path with the plate ridgessubstantially vertical whereby collector sleeve discharge steam inpassing from said outlet passage between said corrugated plates istherein subjected to a scrubbing action which transfers from the steamto the vertical plate ridges still further moisture that forms intowater drops which run down the ridges, and bafile means extendingoutwardly from said sleeve beneath the lower edges of the corrugatedplates to receive said down-running water and cause same to be carriedout from between said plates at the steam-exit side thereof by theseparator discharge steam flowing away from the sleeve above the Waterbetween the plates.

THOMAS RAVESE. EARL V. BENTLEY.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 661,499 Coryell Nov. 13, 1900 1,362,025 Macauley Dec. 14, 19202,058,240 Hobbs Oct. 20, 1936 2,320,343 Bailey June 1, 1943 2,320,345Blizard June 1, 1943 2,368,632 Blizard Feb. 6, 1945 2,395,855 FletcherMar. 5, 1946 2,594,490 Patterson Apr. 29, 1952 FOREIGN PATENTS NumberCountry Date 8,134 Great Britain Mar. 31, 1914 38,431 Netherlands June15, 1936

